[MNG-5613] NPE error when building a reactor with duplicated artifacts

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.1
• Fix Version/s: 3.2.2
• Assignee: Jason van Zyl
• Reporter: Dominique Broeglin
• Created: 06/Apr/14 04:29
• Updated: 04/Apr/20 18:15
• Resolved: 20/May/14 19:34

Description

Using v3.2.1 when building a malformed project containing a duplicated groupId:artifactId I got this rather unhelpful error:

[ERROR] Internal error: java.lang.NullPointerException -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.NullPointerException
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:167)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: java.lang.NullPointerException
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:270)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
	... 11 more

The more helpful error should have been:

org.apache.maven.project.DuplicateProjectException: Project 'com.foo.bar:foo-bar:2.15.0' is duplicated in the reactor
	at org.apache.maven.project.ProjectSorter.<init>(ProjectSorter.java:93)
	at org.apache.maven.DefaultProjectDependencyGraph.<init>(DefaultProjectDependencyGraph.java:53)
	at org.apache.maven.DefaultMaven.createProjectDependencyGraph(DefaultMaven.java:819)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:268)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)

Issue Links

• is duplicated by: MNG-5628 NullPointerException with Maven 3.2.1 when circular dependency exists in POMs
• is duplicated by: MNG-5651 Null pointer exception when trying to execute a mvn build